. >> reporter: republican ron johnson accused the obama administration of covering up the nature of the attack in the weeks following the assault. >> we were misled that there were supposedly protests and then something sprang out of that, an assault sprang out of that. and that was easily ascertained that that was not the fact, and the american people could have known that within days and they didn't know that. >> with all due respect, the fact is we had four dead americans! was it because of a protest or was it because of guys out for a walk one night who decided they'd go kill some americans? what difference at this point does it make? it is our job to figure out what happened and do everything we can to prevent it from ever happening again, senator! >> reporter: clinton focused her testimony on her efforts to fix security issues at the state department. she pointed out that while security costs have gone up, congress has refused requests for more money and cut the state department budget. senator john mccain, a critic of the administration's response to the attacks, said clinton's a